1887
Volume 34 Number 4
  • E-ISSN: 1365-2478

Abstract

ABSTRACT

Borehole surveys are usually commissioned to provide structural details as a guide to further drilling. Conductors remote from the hole are readily detected using EM probes. Vectors can be established by noting variations in wavelength, particularly for reversals of polarity. However, several holes in the same area are required to remove rotational ambiguities, and single axis systems may generate spurious anomalies related to errors in alignment. Consequently, a three‐component sensor has been designed to compare the orthogonal response at each depth. Data are expressed in terms of the invariant parameters of the polarization ellipse, and secondary fields are readily identified.

Loading

Article metrics loading...

/content/journals/10.1111/j.1365-2478.1986.tb00482.x
2006-04-27
2024-04-28
Loading full text...

Full text loading...

References

  1. Cobcroft, R.1985. Downhole omni‐directional EM logging, Bulletin of the Australian Society of Exploration Geophysicists (in prep.).
  2. Cobcroft, R. and Curtis‐Nuthall, R.1983. An omni‐directional downhole EM probe development, Proceedings Biennial Conference, Australian Society of Exploration Geophysics, 50–52.
  3. Fraser, D.C.1978. Resistivity mapping with an airborne multicoil electromagnetic system, Geophysics43, 144–172.
    [Google Scholar]
  4. Hone, I.G. and Pik, P.1980. Sirotem downhole logging Elura, Cobar NSW, The Geophysics of the Elura Orebody, Australian Society of Exploration Geophysics, Special Volume, 170–175.
  5. Jakosky, J.J.1950. Exploration Geophysics (2nd edn), Trija Publishing Company, Los Angeles , California .
    [Google Scholar]
  6. Jones, F.W. and Pascoe, L.J.1971. A general computer program to determine the perturbations of alternating electric currents in a two‐dimensional model of uniform conductivity with an embedded inhomogeneity, Geophysical Journal of the Royal Astronomical Society24, 3–30.
    [Google Scholar]
  7. Keller, G.V. and Frischknecht, F.C.1966. Electrical Methods in Geophysical Prospecting, Pergamon Press, Oxford .
    [Google Scholar]
  8. Lamontagne, Y. and West, G.F.1971. EM response of a rectangular thin plate, Geophysics36, 1204–1222.
    [Google Scholar]
  9. McCracken, K.G., Hohmann, G.W. and Oristaglio, M.L.1980. Why time domain? The Geophysics of the Elura Orebody. Australian Society of Exploration Geophysics, Special Volume, 176–179.
  10. Ogilvy, R.D.1981. Downhole electromagnetic surveys at Woodlawn, Geophysical Case Study of the Woodlawn Orebody, New South Wales, Australia, R.J.Whitely (ed.), Pergamon Press, Oxford , 557–577.
    [Google Scholar]
  11. Oristaglio, M.L. and Hohmann, G.W.1984. Diffusion of electromagnetic fields into a two‐dimensional earth: A finite difference approach, Geophysics49, 870–894.
    [Google Scholar]
  12. Oristaglio, M.L. and Worthington, M.H.1980. Inversion of surface and bore‐hole electromagnetic data for two‐dimensional electrical conductivity models, Geophysical Prospecting28, 633–657.
    [Google Scholar]
  13. Ryu, R., Morrison, H.F. and Ward, S.H.1970. Electromagnetic fields about a loop source of current, Geophysics35, 862–896.
    [Google Scholar]
  14. Spies, B.R.1976. The transient electromagnetic method in Australia, BMR Journal of Australian Geology and Geophysics1, 23–32.
    [Google Scholar]
  15. Swift, CM.1971. Theoretical magnetotelluric and Turam response from two dimensional inhomogeneities, Geophysics36, 38–52.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journals/10.1111/j.1365-2478.1986.tb00482.x
Loading
  • Article Type: Research Article

Most Cited This Month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error